Endoscopic Anterior Subcutaneous Transposition of the Ulnar Nerve Tun Hing Lui, M.B.B.S.(H.K.), F.R.C.S.(Edin.), F.H.K.A.M., F.H.K.C.O.S.  Arthroscopy Techniques  Volume 6, Issue 4, Pages e1451-e1456 (August 2017) DOI: 10.1016/j.eats.2017.06.005 Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 1 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. The volar portal (VP) is about 1 to 2 cm medial and anterior to the medial humeral epicondyle (ME). The dorsal portal (DP) is at the level of the upper border of the medial humeral epicondyle and over the ulnar nerve. (MIS, medial intermuscular septum.) Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 2 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. A subcutaneous pouch is developed by sweeping motion with a trochar cannula (TC) via the dorsal portal (DP). (ME, medial humeral epicondyle; MIS, medial intermuscular septum.) Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 3 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. (A) The volar portal (VP) is the viewing portal, and the dorsal portal (DP) is the working portal. (B) The deep fascia (DF) posterior to the ulnar nerve (UN) is released by the retrograde knife (RK). (ME, medial humeral epicondyle; MIS, medial intermuscular septum.) Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 4 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. The volar portal is the viewing portal, and the dorsal portal is the working portal. The arcade of Struthers (AS) is released posterior to the ulnar nerve (UN) by the endoscopic scissors (ES). Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 5 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. (A) The volar portal (VP) is the viewing portal, and the dorsal portal (DP) is the working portal. (B) The flexor pronator retinaculum (FPR) between the 2 heads of the flexor carpi ulnaris is released by the SuperCut scissors (SS). (ME, medial humeral epicondyle; MIS, medial intermuscular septum; UN, ulnar nerve.) Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 6 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. (A) The dorsal portal (DP) is the viewing portal, and the volar portal (VP) is the working portal. (B) The medial intermuscular septum (MIS) is released by the retrograde knife (RK). (ME, medial humeral epicondyle.) Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 7 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. The volar portal is the viewing portal, and the dorsal portal is the working portal. The fascial tissue embedding the ulnar nerve (UN) is bluntly dissected with an arthroscopic probe (AP). Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions

Fig 8 Endoscopic anterior subcutaneous transposition of the right ulnar nerve. The patient is in the supine position with the upper limb on the side table. (A) The ulnar nerve is placed posterior to the medial epicondyle. The dorsal portal is retracted anteriorly and distally to expose the medial epicondyle and the common flexor origin. The flexor origin is anchored by a curved needle loaded with no. 1 vicryl suture. (B) The suture limbs are retrieved to the dorsal portal and pass under the ulnar nerve. (C) The nerve is transposed anteriorly in the subcutaneous pouch and held in place by a retractor via the volar portal. The suture limbs are passed through the subcutaneous tissue between the volar and dorsal portals by means of a straight-eyed needle. The retractor blade protects the ulnar nerve from injury by the needle. (D) The transposed ulnar nerve is kept in place by suturing of the subcutaneous tissue to the common flexor origin. (CFO, common flexor origin; DP, dorsal portal; MIS, medial intermuscular septum; S, suture; SEN, straight-eyed needle; UN, ulnar nerve; VP, volar portal.) Arthroscopy Techniques 2017 6, e1451-e1456DOI: (10.1016/j.eats.2017.06.005) Copyright © 2017 Arthroscopy Association of North America Terms and Conditions